The NIH Foxhound colony, which employs an outbreeding and inbreeding program, was evaluated to assess the influence of increased homozygosity on overall reproductive performance and ejaculate quality. Conception rates and total number of puppies whelped and number whelped alive were greater in outbred compared to inbred lines. Duration of gestation and number of puppies surviving from birth to weaning were no different between outbred and inbred groups. Ejaculate quality also appeared affected by genotype with outbred males producing a greater average sperm count/ejaculate and sperm count/ml of ejaculate. These results have suggested that: 1) a canine breeding program using dogs with inbreeding coefficients ranging from .125 - .558 can experience reduced reproductive performance; 2) a portion of the infertility associated with conception may be attributed to the male, since inbred studs produced lower quality ejaculates compared to outbred counterparts.